Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide

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Title:Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide
Creators:
Kaválek, Jaromír
Macháček, Vladimír
Sedlák, Miloš
Štěrba, Vojeslav
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 56, 8, pp. 1701-1710

Abstract

The cyclization kinetics of N-(2-methylcarbonylphenyl)-N’-methylsulfonamide (<i>IIb</i>) into 3-methyl-(1<i>H</i>)-2,1,3-benzothiadiazin-4(3<i>H</i>)-one 2,2-dioxide (<i>Ib</i>) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solution. The cyclization is subject to general base and general acid catalysis. The value of the Bronsted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step. In the solutions of potassium hydroxide the cyclization of dianion of the starting ester <i>IIb</i> probably becomes the rate-limiting step.

Title:Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide
Creators:
Kaválek, Jaromír
Macháček, Vladimír
Sedlák, Miloš
Štěrba, Vojeslav
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:56
Number:8
Page Range:pp. 1701-1710
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19911701UNSPECIFIED
ID Code:5096
Item Type:Article
Deposited On:22 Feb 2010 11:30
Last Modified:22 Feb 2010 10:30

Citation

Kaválek, Jaromír; Macháček, Vladimír; Sedlák, Miloš; Štěrba, Vojeslav (1991) Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide. Collection of Czechoslovak Chemical Communications, 56 (8). pp. 1701-1710. ISSN 0010-0765

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